Peeking into the θ vacuum

Vacuum Energy and Θ–vacuum

The highly non-trivial structure of the θ–vacuum encodes many of the fundamental properties of gauge theories. In particular, the response of the vacuum to the θ–term perturbation is sensitive to the existence of confinement, chiral symmetry breaking, etc. We analyze the dependence of the vacuum energy density on θ around two special values, θ = 0 and θ = π. The existence or not of singular beh...

Vector Symmetries and Θ-vacuum

Under very general assumptions we show that Vafa-Witten theorem on vector symmetries in vector-like theories can be extended to some physically relevant gauge theories with non-positive definite integration measure as QCD with a Θ-vacuum term.

Peeking into the Cloud: Toward User-Driven Cloud Management

Peeking into Spammer Behavior from a Unique Vantage Point

cO N fe re N ce re p O rt s 105 from the logs. This can entail considerable developer effort, and getting just the right level of logging can require many iterations: Too much logging can produce unacceptable overhead, but too little will miss key state changes. And even after the logs are captured, analysis remains challenging. D3S attempts to simplify the process of runtime assertion checking...

Θ-vacuum Phase Transitions And/or Symmetry Breaking at Θ = Π

Assuming that a quantum field theory with a θ-vacuum term in the action shows nontrivial θ-dependence and provided that some reasonable properties of the probability distribution function of the order parameter hold, we argue that the theory either breaks spontaneously CP at θ = π or shows a singular behavior at some critical θc between 0 and π. This result, which applies to any model with a pu...